1. Field of the Invention
The present invention relates to a semiconductor light emitting element such as a light emitting diode (LED).
2. Description of the Related Art
The semiconductor light emitting element is generally fabricated typically by forming, on a growth substrate, an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer, and then by forming an n-electrode and a p-electrode which apply a voltage to the n-type semiconductor layer and the p-type semiconductor layer. When the semiconductor light emitting element is fabricated to use a nitride-based semiconductor material, a sapphire substrate is used as a growth substrate, for example.
Japanese Patent Application Kokai. 2000-232238 discloses a nitride semiconductor light emitting element which comprises an active layer, a barrier layer and a buried part consisting of the same material as the material for the barrier layer, which is defined by the interface extending to the periphery surrounding a threading dislocation in the active layer. Japanese Patent Application Kokai No. 2007-150076 discloses a nitride semiconductor light emitting element which comprises a substrate, an active layer and a superlattice layer made of nitride semiconductor wherein a pit formation layer for generating a pit is provided at the end of threading dislocation generated on the nitride semiconductor layer at the side of the substrate. Further, Japanese Patent Application Kokai No. 2013-41930 discloses a nitride semiconductor light emitting element which comprises an n-type nitride semiconductor layer, a V-pit generation layer, an intermediate layer, a multiple quantum well light emitting layer, and a p-type nitride semiconductor layer which are provided in that order wherein a V-pit is partly formed in the multiple quantum well light emitting layer, and an average position of starting point of the V pit is located in the intermediate layer.